1. Technical Field
The present disclosure relates to a computer wake up circuit, and particularly to a computer wake up circuit used for multiple serial devices waking up a computer from a sleep state.
2. Description of Related Art
With the rapid development of personal computers, development of high performance components of a computer have brought about a corresponding increase in power use. Therefore, wasting of power becomes more likely if the computer is not changed to a power saving state when not in use. Typically, a wake up circuit is included when designing computer power management for solving the above problem. There is usually a sleep/awake button on a keyboard of a computer that is connected to the inner wake up circuit of a motherboard of the computer. The button is pressed by a user for putting the computer to sleep. Then when the user wishes, presses the same button again to wake up the computer.
The typical wake up circuit receives control signals from the sleep/awake button or peripheral devices to wake the computer from a sleep state. However, different peripheral devices may output different control signals. Some of the peripheral devices output special control signals that are not compatible with the wake up circuit. The wake up circuit sometimes cannot respond to the special control signal effectively to wake up the computer. Also, the control signals from the peripheral devices may be easily influenced by control signals from other chipsets and noise signals, which the cause the wake up circuit to fail.